The team combined a fusion protein into a microneedle patch made from a biocompatible polymer. The patch’s needles are biodegradable, releasing vaccine into the skin as they dissolve.
Mice receiving a conventional inactivated vaccine and the microneedle-patch booster better maintained an antibody response against the influenza virus compared to those that received the traditional vaccine alone, according to a study published in the Journal of Controlled Release.
The researchers immunized mice with an inactivated influenza vaccine and, four weeks later, gave them either an intramuscular injection of the fusion protein, the microneedle patch with the protein or a placebo microneedle patch.
Then, the team assessed whether the booster changed the immune response that is triggered by traditional vaccines. The mice were presented with H1N1 and H3N2 influenza viruses and monitored daily, according to the team, for 14 days.
Mice that were given the microneedle patch booster showed greater survival and cellular immune responses compared to those that received a placebo.
“Our study demonstrates that M2e-based vaccines greatly improve immune responses and strengthen protective functions against influenza virus infection,” Baozhong Wang, associate professor at the Institute for Biomedical Sciences at Georgia State, said in prepared remarks. “We found that a skin-applied 4M2e-tFliC microneedle patch boosted immunization to seasonal vaccine recipients and may be a rapid approach to increasing the protective efficacy of seasonal vaccines in response to influenza virus challenges. Thus, the M2e antigen is a promising candidate for the development of universal influenza vaccines.”